Ever looked at your fuse board and thought: "What are all these warning labels for?"
Here’s a quick guide to the most common stickers you’ll see on a UK consumer unit — and why they matter:
⚡ 𝟭. 𝗠𝗮𝗶𝗻 𝗦𝘄𝗶𝘁𝗰𝗵 𝗪𝗮𝗿𝗻𝗶𝗻𝗴 𝗟𝗮𝗯𝗲𝗹 "Warning Isolate Supply Before Opening Cover"
This reminds you that live parts are still present even with circuit breakers off and in order to isolate the whole supply the main switch should be in the off position.
⚡ 𝟮. 𝗥𝗖𝗗 𝗧𝗲𝘀𝘁 𝗟𝗮𝗯𝗲𝗹 "This installation, or part of it, is protected by a device......."
This tells you to test your RCDs every 3 months by pressing the ‘T’ or ‘Test’ button — it could save your life!
⚡ 𝟯. 𝗜𝗻𝘀𝗽𝗲𝗰𝘁𝗶𝗼𝗻/𝗧𝗲𝘀𝘁 𝗦𝘁𝗶𝗰𝗸𝗲𝗿 "This installation should be periodically inspected......"
Shows date of last inspection & recommended next inspection date. Domestic homes usually need one every 5 years if rented and 10 years if owned.
⚡ 𝟰. 𝗗𝗮𝗻𝗴𝗲𝗿/𝗪𝗮𝗿𝗻𝗶𝗻𝗴 𝗟𝗮𝗯𝗲𝗹𝘀 "This installation has more than one power supply..."
Used in special setups like solar or EV chargers — alerting electricians to hidden risks.
⚡ 𝟱. 𝗗𝗮𝗻𝗴𝗲𝗿/𝗪𝗮𝗿𝗻𝗶𝗻𝗴 𝗟𝗮𝗯𝗲𝗹𝘀 "Circuit No.s _ _ _ do not have provision for earthing metal equipment"
Indicates the lack of an earthing conductor usually in a lighting circuit and warns against installing metal class 1 light fittings.
⚡ 𝟲. 𝗗𝗮𝗻𝗴𝗲𝗿/𝗪𝗮𝗿𝗻𝗶𝗻𝗴 𝗟𝗮𝗯𝗲𝗹𝘀 "Safety electrical connection do not remove"
Used to alert individuals about the presence of an electrical safety connection, usually an earthing connection, that should not be disconnected.
⚡ 𝟳. 𝗗𝗮𝗻𝗴𝗲𝗿/𝗪𝗮𝗿𝗻𝗶𝗻𝗴 𝗟𝗮𝗯𝗲𝗹𝘀 "This installation has wiring colours to two versions...."
Alerts electricians to the use of both former (red/black) and harmonised (brown/blue) cable colours within the installation.
✅ Top Tip: Never remove or cover these stickers they’re there to protect you, your family, and any future electricians working on your property.
Want to know more? Get in touch with me, Tony, your local electrician in High Wycombe today.